"Mood Foods"

An excerpt from a paper on nutritional and psychological issues:

MOOD FOODS
Whether in reference to being a comfort food, an aphrodisiac or the like, people all over the world have claimed links between ingesting certain foods and a resulting emotional effect. Asides from the classic aphrodisiacs of oysters and chocolate, spices such as saffron, vanilla, and even onions have lengthy reputations for sparking romantic desire. Evidence for most mood foods remains anecdotal, but chemical analysis has revealed some firm links between certain foods and specific bodily reactions or emotional states.

The operant principle with most of the mood foods is that foods have a varying quantity of precursors to neurotransmitters, which are the chemical messengers that carry information from one cell to another. After these precursors are ingested, the body synthesizes them into serotonin, dopamine, norepinephrine, and so on, each of which have a distinct function (Appendix B). The more precursors a food has, the more neurotransmitters that can be potentially created . One should note that most psychotropic medicines such as the antidepressants Prozac, Paxil, and Zoloft operate on a similar principle, since these medicines either increase the production of or maintain the levels of a specific neurotransmitter. With these three medicines, serotonin would be the affected neurotransmitter, since they are SSRI’s (selective serotonin reuptake inhibitors) that keep serotonin from breaking down after leaving nerve cells.

Knowing the basic mechanism of mood foods, what are some examples of “proven” mood foods? Before going into specifics, one of the caveats of this research is that foods are complex substances with many constituent parts that sometimes deviate from expected operation. For example, turkey is a food that contains the amino acid tryptophan, which is a precursor to serotonin. A commonly held belief was that the sleepiness following a Thanksgiving turkey dinner was due to the tryptophan’s conversion into serotonin, which was known to help promote sleep. However, research showed that the tryptophan couldn’t affect the brain because the protein in the turkey meat inhibits tryptophan absorption . The more plausible explanation for the post-meal drowsiness was from overeating, even though turkey has definite levels of “pre-serotonin.”

That being said, the general rubric of mood foods, discovered by Judith and Richard Wurtman, is that carbohydrate-filled foods increase serotonin production, which promotes a relaxed, calm feeling . Conversely, protein-filled foods like meats and dairy contains high levels of tyrosine, which is the precursor to dopamine, norepinephrine and epinephrine. The presence of these neurotransmitters is linked to heightened levels of alertness and energy . In order to maximize the effectiveness of these foods, the Wurtmans advocate consuming each macronutrient separately rather than combining them.

Macronutrients such as carbohydrates and protein are not the only source for the precursors to neurotransmitters, as vitamins and minerals also play a similar role. In fact, some psychologists have demonstrated that patients with specific mental disorders exhibit chronic deficiencies in some nutrients. For instance, Folic Acid, long known to be a necessary nutrient for a healthy pregnancy, was found to be deficient in many psychiatric patients diagnosed with depression. By consuming the same amount of folic acid as found in a glass of orange juice, some patients found relief from their depressive symptoms. Researchers also found that individuals with selenium deficiency were “more anxious, irritable, hostile, and depressed than their non-lacking counterparts. ” Eating only one or two Brazil nuts was able to compensate for this deficiency.

Few, if any therapists would claim that psychological disorders could be prevented or treated solely through dietary means alone (though with mild cases, this is possible). A more moderate, accurate claim might be that an individual who develops symptomology for a disorder while following a proper, balanced diet would be more likely to have a genuine case of said disorder than someone with dietary inadequacies. During diagnostic sessions where a therapist is evaluating a potential client, knowledge about the links between nutritional deficiency and altered mental states can render a more accurate determination than a practioner who isn’t “in the know.” This is one notable example where the foods one does or does not eat can affect their mental state.

Serotonin: The serotoninergic system is known to modulate mood, emotion, sleep and appetite and thus is implicated in the control of numerous behavioural and physiological functions. Decreased serotoninergic neurotransmission has been proposed to play a key role in the aetiology of depression.

Serotonin is believed to play an important part of the biochemistry of depression, bipolar disorder and anxiety. It is also believed to be influential on sexuality and appetite

Norepinephrine: One of the 'stress hormones' [that] affects parts of the human brain where attention and impulsivity are controlled. Along with epinephrine this compound affects the fight-or-flight response, activating the sympathetic nervous system to directly increase heart rate, release energy from fat, and increase muscle readiness.

Dopamine: Dopamine is critical to the way the brain controls our movements and is a crucial part of the basal ganglia motor loop. Shortage of dopamine…causes Parkinson's disease… In the frontal lobes, dopamine controls the flow of information from other areas of the brain. Dopamine is commonly associated with the 'pleasure system' of the brain, providing feelings of enjoyment and reinforcement to motivate us to do, or continue doing, certain activities. Disruption to the dopamine system has also been strongly linked to psychosis and schizophrenia.

GABA: Gamma-aminobutyric acid, in humans, acts at inhibitory synapses in the brain and spinal cord. In other words, where the prior three neurotransmitters were “excitatory”, GABA is “inhibitory,” meaning that it ceases processes that other neurotransmitters had begun.